填充颗粒形貌对复合固体推进剂力学性能影响的有限元数值分析

In order to study the influence of filling particle morphology on the microscopic mechanical properties of composite solid propellants,a representative volume elements(RVE)computational model was established at the microscopic level by considering the phase interface and particle morphology.The influence of different microscopic particle morphologies on the macroscopic mechanical properties of composite solid propellants,including different mixing particle shapes,mixing particles with gradation and irregularly filled particles,was investigated through the introduction of a cohesive zone model(CZM).The results show that: when the model filler particles are all small particles of 150 μm diameter,the filler morphology has little effect on the mechanical properties, while the filler particles are large particles with a grain size of 290 μm to 420 μm,the more rounded the particles are,the more likely to occur “dehumidification” damage at the interface,resulting in a significant decrease in the mechanical properties;in the case of circular filler with the same large particles,the morphology of small particles has a greater impact on the initial modulus,and if the aspect ratio of small particles increases from 1 to 2,the initial elastic modulus decreases,while the maximum tensile strength changes are smaller;in the case of the same ellipsoidal filler with large particles,the maximum tensile strength of the filler with small round particles is larger;the interfacial failure modes are different in the polygonal filled particles model,the circular filled particles model,mechanical properties of the polygonal filling model are significantly higher than that of the circular filled particles.Therefore,it can be concluded that the mechanical properties of the propellant are better when there is a large difference in the morphology of the finer filler particles.